Risk Factor Selection Process
Third, to prioritize the risk factors for inclusion in PERCH,
we selected those with the highest population-attributable
fractions or with the strongest effects, while balancing pragmatic
concerns, such as feasibility, cost of data collection,
analytic plans, and comparability with existing data from
countries not represented in the PERCH study. An external
advisory group of pneumonia experts (the Pneumonia
Methods Working Group) [1] that was convened by the study
team assisted with further prioritization and suggested new
risk factors to assess.